Multicomponent improved vehicle fuel economy system

ABSTRACT

A semitrailer comprising a main frame having a hitch, an axle assembly connected to the main frame, the axle assembly including at least two wheels for rotation relative to the main frame, a fairing connected to an underside of the semitrailer intermediate the hitch and the axle assembly, the fairing including a pair of lateral surfaces, a bottom surface spaced from the underside of the semitrailer, and a leading surface, wherein the leading surface includes an intake opening, and wherein at least one of the bottom surface or the lateral surfaces includes an exit opening, and a flow path fluidly connects the intake opening and the exit opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is an International Application claimingpriority to U.S. Provisional Application No. 61/838,677 filed Jun. 24,2013; U.S. Provisional Application No. 61/838,111 filed Jun. 21, 2013;U.S. patent application Ser. No. 13/839,662 filed Mar. 15, 2013; andU.S. Provisional Application No. 61/723,506 filed Nov. 7, 2012; theentire disclosures of which are expressly incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to overland vehicles and moreparticularly to decreasing the aerodynamic drag of such vehicles andmore particularly to semitrailers.

In another configuration, the present disclosure provides a fairingsystem for semitrailers and particularly for semitrailers having amovable axle assembly—often referred to as a bogie or tandem. Forpurposes of the present disclosure, the term axle assembly is intendedto be interchangeable with bogie, tandem or other equivalent terms.

BACKGROUND ART

Most of today's tractor-trailers get about 6-7 mpg of fuel leavingsignificant potential for improving fuel economy of tractor-trailers.Reducing the fuel consumption of tractor-trailers would directly impacttransportation costs of goods, serving businesses and consumers alike.

Fuel consumption of a tractor-trailer is influenced by the amount ofdrag forces incurred by the vehicle while traveling. As the drag forcesincrease, fuel consumption also increases. One area of a semitrailerwhere drag forces are high is the undercarriage of a semitrailer.Another area of the semitrailer where aerodynamic forces are high is therear end of a semitrailer container. When the tractor-trailer istraveling, air flows under and around the semitrailer, placingsignificant drag forces on the wheels, undercarriage and rear of thetruck. The tractor-trailer must use more power to overcome the drag,thereby increasing fuel consumption. Thus, it is most desirable toreduce drag beneath the undercarriage and at the rear end of asemitrailer.

What is needed then is a drag reduction system for a semitrailer thatimproves fuel economy.

It would, therefore, be desirable to provide a drag reduction system fora semitrailer that overcomes the aforesaid and other disadvantages.

DISCLOSURE OF INVENTION

The present invention provides a fairing system for semitrailers fordecreasing aerodynamic drag. One configuration of the invention is adrag force reduction system comprising a semitrailer having a main frameextending along a longitudinal axis and a subframe movably connected tothe main frame between a first position along the longitudinal axis anda second position along the longitudinal axis. An axle assembly isattached to the subframe, wherein the axle assembly includes an axle, aplurality of wheels and a suspension. A fairing is located under themain frame and is separated from the axle assembly along thelongitudinal axis by a given spacing. The fairing is movable relative tothe main frame to maintain the given spacing between the axle assemblyand the fairing independent of the subframe and hence axle assemblybeing in the first position or the second position. In oneconfiguration, the fairing is slidably connected to the main frame. Inanother configuration, the fairing is slidably connected to the axleassembly.

The fairing can include a fairing frame having a mounting portion and aframe retaining portion, wherein the mounting portion is movablerelative to the retaining portion along the longitudinal axis. In oneconfiguration, the fairing is affixed to one of the axle assembly andthe subframe at a given spacing, which may be adjustable within apredetermined fairing range of motion. In one configuration, the fairingis connected to the subframe and translatable relative to the subframe.The fairing includes an aerodynamic structure formed of one of metal,aluminum, plastic, ABS, Poly Carbonate, TPO and other polymers.

In one configuration, the fairing includes a bottom and a leading apexformed of a plurality of converging planar regions. The fairing includesa bottom surface and a trailing surface, a leading surface and lateralsurfaces, the bottom surface and the trailing surface substantiallyenclosing a volume beneath the semitrailer. A plurality of lightingelements can be disposed along at least a portion of the fairing.

The fairing can include an intake opening and at least one flow pathfluidly connecting the intake opening and an exit-opening formed in thefairing. The at least one flow path may include at least one ventingduct extending from the intake opening to the at least one exit-opening.The at least one exit-opening has a cross-sectional area less than across-sectional area of the intake opening. The at least oneexit-opening can have a cross-sectional area equal to a cross-sectionalarea of the intake opening.

In a configuration, the main frame further includes a plurality ofelongate beams extending along a longitudinal axis and a plurality ofcross beams connected to the elongate beams and extending transverse tothe longitudinal axis, an upper surface of the cross beams and theelongate beams supporting a decking, and the decking, the elongate beamsand the cross beams defining a plurality of cavities opening to anunderside of the semitrailer, wherein a covering on an underside of thesemitrailer substantially occludes the plurality of cavities. Thecovering can be connected to the elongate beams and the cross beams. Aportion of the covering can be disposed between the wheels and one ofthe elongate beams and the cross beams. The covering can be selectedfrom the group consisting of a polymer, composite, laminate, metal, andplastic.

In another configuration, a semitrailer comprises a main frame, hitch awheel set connected to the main frame, the wheel set including at leasttwo wheels for rotation relative to the main frame, a closable containeron the main frame, the container having a rear end and a pair of doorsmovable between a closed position and an open position, each doorhingedly connected to the container to pivot about a vertical axis, avertical flap, at least an upper hinge and a lower hinge hingedlyconnected to one of the doors and the vertical flap to pivot thevertical flap about a vertical axis, and an interconnector extendingbetween the upper hinge and the lower hinge, such that upon movement ofthe lower hinge from an open configuration to a closed configuration,the upper hinge moves from an open configuration to a closedconfiguration. The interconnector may have a u-shaped base having twolegs and a closed end rotatably connected to one of the doors and twolegs, each leg pivotally coupled to the upper hinge and lower hinge,respectively. The interconnector, in one configuration, is a barconnected to the upper hinge and lower hinge. The semitrailer canfurther comprise a horizontal top flap and a top hinge connected to oneof the doors and the horizontal top flap to pivot the horizontal topflap about a horizontal axis. The semitrailer can further include afirst link having a first end pivotally connected to the horizontal topflap and a second end pivotally connected to a slider, wherein theslider is connected to the door to vertically slide along a verticalaxis. In a configuration, a vertical flap and horizontal top flap ishingedly connected to each door. Each vertical flap and horizontal topflap can be an aerodynamic panel formed of a material selected from thegroup consisting of plastic, metal, fabric, cardboard, and framedfabric.

In yet another configuration, a semitrailer includes a main frame, awheel set connected to the main frame, the wheel set including a leadingaxle and a trailing axle, each of the leading axle and the trailing axlehaving at least two wheels for rotation relative to the main frame, anda diffuser extending about a portion of the leading axle, the diffuserextending along a majority of the distance between the wheels of leadingaxle, wherein the diffuser directs a passing air flow toward the ground.The diffuser can extend rearward to the trailing axle and may encompassa portion of the trailing axle. The diffuser locates a portion of theleading axle and the trailing axle between the diffuser and the mainframe.

In yet another configuration, a semitrailer includes an underside, ahitch, a wheel set, a frame connected to the underside of thesemitrailer intermediate the hitch and wheel set, the frame having afront portion, a back portion, a bottom portion and two opposing lateralsides, a skin enclosing at least one portion of the frame, and a backunit for mounting to a back planar surface of the semitrailer, the backunit having (i) first and second frames formed of a plurality of struts,each frame having a base portion arranged proximate the back planarsurface of the semitrailer and a protruding portion of the framearranged distal to the back planar surface of the semitrailer, whereinthe base portion of the first frame circumscribes a first portion of theback planar surface of the semitrailer and wherein the base portion ofthe second frame circumscribes a second portion of the back planarsurface of the semitrailer, and (ii) a material substantially enclosingthe back unit frames. The first and second frames can each formapproximately ½ of a pyramid. The back planar surface of the semitrailercan include fixed hinges and hinge bolts for receiving a first terminalend of each strut of the frame, wherein the first termination end ofeach strut includes a pivoting connector arranged to engage one of thehinge bolts.

In another configuration, a semitrailer comprises a main frame having ahitch, an axle assembly connected to the main frame, the axle assemblyincluding at least two wheels for rotation relative to the main frame, afairing connected to an underside of the semitrailer intermediate thehitch and the axle assembly, the fairing including (i) a pair of lateralsurfaces, (ii) a bottom surface spaced from the underside of thesemitrailer, and (ii) a leading surface. In a further configuration, theleading surface includes an intake opening, and wherein at least one ofthe bottom surface or the lateral surfaces includes an exit opening, anda flow path fluidly connects the intake opening and the exit opening. Inone configuration, the fairing is movable relative to a main frame ofthe semitrailer to maintain a given spacing between the axle assemblyand the fairing independent of the axle assembly being in a firstposition or a second position. The main frame can further includes aplurality of elongate beams extending along a longitudinal axis and aplurality of cross beams connected to the elongate beams and extendingtransverse to the longitudinal axis, an upper surface of the cross beamsand the elongate beams supporting a decking and the decking, theelongate beams and the cross beams defining a plurality of cavitiesopening to an underside of the semitrailer, wherein a covering on anunderside of the semitrailer substantially occludes the plurality ofcavities. The covering in one configuration is connected to the elongatebeams and the cross beams. A portion of the covering can be disposedbetween the wheels and one of the elongate beams and the cross beams,wherein the covering comprises a material selected from the groupconsisting of a polymer, composite, laminate, metal, and plastic.

In one configuration, the lateral surfaces are separated by a distanceand the leading surface substantially spans the distance, wherein thebottom surface spans an area bounded by the lateral surfaces and theleading surface and includes an angled portion extending away from theunderside of the semitrailer. In this configuration, the leading surfacedefines a bow having a shape selected from the group consisting of flat,curved, arched, angled, tumblehoned, plumed, raked, and spooned. Theleading surface can includes first and second venting ducts extendingfrom an intake opening in the leading surface to the exit—opening ineach corresponding lateral surface, wherein air exiting theexit-openings reduces a pressure on an outside surface of the fairingand/or on at least one of (i) the bottom surface of the fairing, and(ii) the lateral surface.

In yet another configuration, the semitrailer comprises a back unit formounting to a back planar surface of the semitrailer, the back unithaving (i) first and second frames formed of a plurality of struts, eachframe having a base portion arranged proximate the back planar surfaceof the semitrailer and a protruding portion of the frame arranged distalto the back planar surface of the semitrailer, wherein the base portionof the first frame circumscribes a first portion of the back planarsurface of the semitrailer and wherein the base portion of the secondframe circumscribes a second portion of the back planar surface of thesemitrailer, and (ii) at least one skin substantially enclosing thefirst and second frames. The semitrailer in one configuration includes aclosable container on the main frame, the container having a rear endand a pair of doors movable between a closed position and an openposition, each door hingedly connected to the container to pivot about avertical axis, a vertical flap, at least an upper hinge and a lowerhinge hingedly connected to one of the doors and the vertical flap topivot the vertical flap about a vertical axis, and, an interconnectorextending between the upper hinge and the lower hinge, such that uponmovement of the lower hinge from an open configuration to a closedconfiguration, the upper hinge moves from an open configuration to aclosed configuration. A diffuser extends about a portion of a leadingaxle and a trailing axle of the axle assembly, wherein the diffuserdirects a passing air flow toward the ground.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing features of this invention, as well as the inventionitself, may be more fully understood from the following description ofthe drawings in which:

FIG. 1 is a left side view of a drag force reduction system showing afairing system and a rear flap system for a semitrailer, the semitrailerhaving a moveable axle assembly.

FIG. 2 is a perspective view of the fairing system coupled to anundercarriage of the semitrailer.

FIG. 3 is a perspective view of the fairing system moveably coupled tothe undercarriage of the semitrailer.

FIG. 4 is a perspective view of an integral fairing system moveablycoupled to the undercarriage of the semitrailer.

FIG. 5 is a partial perspective view of the undercarriage of thesemitrailer showing a diffusor having channels.

FIGS. 6A and 6B are partial left side views of the semitrailer showing atelescoping configuration of the fairing system.

FIG. 7 is a perspective view of the fairing showing an intake openingand an exit opening fluidly coupled by a venting duct.

FIG. 8 is a rear perspective view of the semitrailer showing the rearflap system.

FIG. 9 is a partial perspective view of the rear end of the semitrailershowing a portion of the rear flap system mounted to one door of asemitrailer.

FIG. 10 is a side view of a semitrailer showing a second configurationof the drag force reduction system.

FIG. 11 is a front perspective view of the second configuration of thefairing system.

FIG. 12 is a perspective view of a rear-end of the semitrailer showing aframe of a back unit without a skin.

FIG. 13 is a perspective view of one-half of a rear-end back unit.

FIG. 14 is a perspective view of one-half of a rear-end back unit.

FIG. 15 is a perspective view of the bow of the second configuration ofthe fairing system showing the venting system.

FIG. 16 is a perspective view of one-half of the fairing having aventing system.

FIG. 17 is a side view of the second configuration of the fairingsystem.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

At the outset, it should be appreciated that like drawing numbers ondifferent drawing views identify identical structural elements of theinvention. While the present invention is described with respect to whatis presently considered to be the preferred embodiment, it is understoodthat the invention is not limited to the disclosed embodiment.

Furthermore, it is understood that the invention is not limited to theparticular methodology, materials, and modifications described and assuch may vary. It is also understood that the terminology used herein isfor the purpose of describing particular elements only, and is notintended to limit the scope of the present invention, which is limitedonly by the appended claims.

The drag force reduction system increases fuel economy fortractor-trailer trucks, straight trucks, cargo carriers, school busesand the like by reducing drag under the vehicle and off the back of thevehicle.

Averting now to the Figures, FIGS. 1 and 3 show a fairing system 100coupled to an undercarriage 10 of a semitrailer 12. As shown in FIGS.1-4, the semitrailer 12 includes a main frame 14 extending along alongitudinal axis 16, wherein the longitudinal axis 16 is generally themajor axis of the semitrailer 12 and extends along the length of thesemitrailer 12.

The semitrailer 12 can include any of the standard components known inthe art including, but not limited to a coupling such as king pin,lighting, hoses, cabling or wiring. The semitrailer 12 can also includelanding gear as known in the art. It is understood the semitrailer 12can be any of the known configurations including but not limited to dumpsemitrailers, container semitrailers, chip van, refrigerated, log,flatbed or tank semitrailer.

The semitrailer 12 includes a subframe 18 as shown in FIG. 3 movablyconnected to the main frame 14. In one configuration, the subframe 18 ismovably connected to the main frame 14 by means of a plurality of tracks20, such that the subframe 18 can move along the tracks 20 to be locatedat any of a number of positions along the longitudinal axis 16. The useof a subframe 18 and interconnection to the main frame 14 is known inthe art. Representative disclosures include U.S. Pat. Nos. 5,314,201;5,232,234; 5,137,296 and 6,279,933, each of which is hereby expresslyincorporated by reference.

The interconnection of the subframe 18 and the main frame 14 provide forthe subframe 18 to be located at any of a multitude of positions along arange of motion, wherein the range of motion can be as long as ten (10)feet.

The subframe 18 carries an axle assembly 30 and the axle assembly 30includes at least an axle 32, a plurality of wheels 34, and a suspension(not shown). In many configurations, the axle assembly 30 includesbrakes, hydraulics, air lines, and connections to air ride systems asknown in the art. It is understood the axle assembly 30 can include one,two or more axles, wherein each axle can include two or more wheels.Thus, as well known in the art, the motion of the axle assembly 30relative to the main frame 14 locates the wheels 34 at correspondinglydifferent locations along the longitudinal axis 16. Thus, for example,locating the wheels 34 closer to a front of the main frame 14 allows foreasier maneuverability in congested areas and tight-radius turns, suchas at an intersection. In addition, selective location of the axleassembly 30 provides for improved load distribution.

The fairing system 100 further includes a fairing 102 located under themain frame 14 and spaced from the axle assembly 30 along thelongitudinal axis 16 by a given distance. In select configurations, thegiven distance is adjustable, typically within a faring range of motionless than approximately three (3) feet. Further, the faring range ofmotion extends from a proximate position locating a portion of thefairing 102 approximately one (1) inch from the wheels 34 of the axleassembly 30 to approximately three (3) feet from the wheels 34.

The fairing 102 produces a smooth outline and reduces drag with respectto passing airflow, such as induced when the semitrailer 12 is beingtowed by a tractor. The fairing 102 can extend along the longitudinalaxis 16 from adjacent landing gear 36 to adjacent the wheels of the axleassembly—subject to the fairing range of motion as set forth above. Itis understood the fairing 102 can extend along the longitudinal axis 16for an little as ten percent (10%) of the distance between the wheels 34and the landing gear 36 to one-hundred ten percent (110%) of thedistance thereby encompassing the landing gear 36. In one configuration,the fairing 102 extends along approximately half the distance betweenthe landing gear 36 and the axle assembly 30. Advantageously, thefairing 102 extends as close to the roadway as operationally possibleand is at least as wide as the width of the axle assembly 30. Thefairing 102 can extend across substantially the entire width of thesemitrailer or a percentage of the width. Thus, the width of the fairing102 may encompass the width of the wheels 34, or terminate within thespacing between the wheels 34. It is further contemplated the fairing102 can have lateral extensions located outside the width of the wheels34, and thus can locate at least a portion of the wheels 34 between thelateral extensions in select positions of the fairing 102 relative tothe axle assembly 30.

The fairing 102 is movable relative to the main frame 14 such that asthe subframe 18 (and axle assembly 30) are moved along the longitudinalaxis 16 relative to the main frame 14, the given spacing between theaxle assembly 30 and the fairing 102 is maintained. That is, theposition of the fairing 102 relative to the axle assembly 30 isindependent of the position of the axle assembly 30 relative to the mainframe 14. As the axle assembly 30 is moved relative to the main frame 14(thereby accommodating a different turning-radius or load distribution)the fairing 102 is maintained in a constant position relative to thewheels 34 of the axle assembly 30.

It has been found that by locating a rear edge 104 of the fairing 102 asnear as possible to the wheels 34 of the axle assembly 30, theefficiency of the semitrailer 12 increases (or conversely the requiredgas consumption decreases). However, it is understood that various roadconditions, loads or environmental conditions may require the spacingbetween the fairing 102 and the wheels 34 be adjusted within the fairingrange of motion. That is, the aerodynamic efficiency of the fairing 102can be dependent on the specific spacing of the fairing 102 and thewheels 34 for a given set of operating conditions. Thus, the fairing 102can be mounted at any of the variety of locations along the faring rangeof motion relative to the axle assembly 30 to maximize the effectivenessof the fairing 102. However, once the relative position of the fairing102 relative to the axle assembly 30 has been temporarily fixed orselected, the fairing 102 and the axle assembly 30 translate as a unitrelative to the semitrailer main frame 14.

The fairing 102 can include a fairing frame 106 as shown in FIG. 3 uponwhich is retained or disposed a covering 108 to form an aerodynamicshape. The aerodynamic shape of the fairing 102 can be any shape thatreduces aerodynamic drag. The fairing frame 106 can define any of avariety of shapes from curvilinear surfaces, such as a dome to a pointor a pyramidal shape.

As shown in FIGS. 3 and 4, the fairing 102 can include lighting 110 forsafety, visibility and marketing. The lighting 110 can be any known inthe art including LED, wherein control of the lighting can be providedby a tractor or control within the fairing. In one configuration, thelighting 110 is disposed along the perimeter edge of the lateral surfaceof the fairing.

While the fairing 102 is described in terms of a fairing frame 106 andcovering 108, it is understood the fairing frame 106 and covering 108can be a substantially integral or blended in structure, such as bymolding or forming, as show in FIG. 4. In this construction, the fairing102, or at least portions of the fairing 102, can be formed by moldingpolymer. Alternatively, the fairing 102 can be formed of a combinationof frame sections and integral (molded) sections.

The mounting or connection of the fairing 102 relative to thesemitrailer 12 can be accomplished through a variety of configurations.

In one configuration, the main frame 14 includes at least one and can beas many as a multitude of tracks 112 extending along the longitudinalaxis 16. The fairing frame 106 includes a corresponding number of slidesor bosses 114 slidably received within the tracks 112 such that thefairing 102 can move relative to the main frame 14. The fairing frame106 is further connected to the axle assembly 30 or the subframe 18,such that as the axle assembly 30 is moved relative to the main frame14, the fairing 102 is correspondingly moved within the tracks 112 alongthe longitudinal axis 16. This maintains the relative spacing betweenthe fairing 102 and the wheels 34 of the axle assembly 30 independent ofmovement of the main frame 14 relative to the axle assembly 30 and/orsubframe 18.

In one configuration, it is contemplated the slides 114 of the fairing102 can include setoffs or standoffs 116 which space a portion of thefairing frame 106 below the subframe 18 to avoid interference with thesubframe 18.

It is contemplated the connection of the fairing 102 to the axleassembly 30 (subframe 18) is adjustable within the fairing range ofmotion, such as the previously disclosed one (1) inch to three (3) feet.

In a further configuration as shown in FIGS. 6A and 6B, the fairing 102includes a mounting portion 90 and a frame retaining portion 92, whereina telescoping or slide interconnection is formed between the mountingportion 90 and the frame retaining portion 92. The mounting portion 90is configured to affix to the subframe 18 or axle assembly 30 and theframe retaining portion 92 is configured for supporting or defining thefairing 102. The range of motion between the mounting portion 90 and theframe retaining portion 92 define the fairing range of motion—from one(1) inch to three (3) feet. The mounting portion 90 and frame retainingportion 92 can be releasably, but fixedly connected so that an operatorcan adjust and then trail the semitrailer 12 with the fairing 102 in aselected position relative to the wheels 34 (axle assembly 34). In thisconfiguration, as the fairing frame 106 is mounted only to the axleassembly 34 (or the subframe 18) rather than the main frame 14 and thereis no need for the tracks 112 along the underside of the main frame 14.

It is contemplated the fairing 102 can have a substantially open rearend, a closed rear end or a partly occluded rear end. That is, thefairing 102 can define the air flow deflecting surface wherein the rearof the fairing (facing the axle assembly) is open forming a pocket.Alternatively, the fairing 102 can define a substantially enclosedvolume precluding ingress or egress. In a further configuration, thefairing 102 can have a partially occluded rear end, such as by panels orsections inhibiting a flow into the pocket of the fairing from the rear.Depending on the specific configuration, the panels can be located atdifferent positions along the longitudinal axis. Thus, some panels in atthe rear of the fairing can be proximal to the axle assembly and otherpanels can be distal to the axle assembly.

As shown in FIG. 7, the fairing 102 can include an intake opening 118and at least one flow path fluidly connecting the intake opening 118 andan exit-opening 120. In a configuration, the flow path fluidlyconnecting the intake opening 118 and the exit-opening 120 is formedfrom at least one venting duct 122. The exit-opening 120 can have across-sectional area less than or equal to a cross-sectional area of theintake opening 118.

In a further configuration, as shown in FIG. 5, the disclosure providesa diffuser 300 for reducing air flow between spaced axles in the axleassembly 30, such as a tandem. The diffuser 300 defines a generallycurvilinear surface at least partially encompassing a diameter of atleast one of a leading and a trailing axle in the axle assembly, asshown in the pictures. In one configuration, the diffuser 300 extendsalong the bottom portion of the axles. In a further configuration, thediffuser 300 substantially encompasses the leading and trailing axle.The diffuser can be a single piece construction or multiple piececonstruction, wherein the multiple pieces are assembled about the axles.

The diffuser 300 can include channels 310 extending generally along thelongitudinal axis 16, wherein the channels 310 direct air flow downwardand just behind the wheels 34, thereby intersecting road spray andsubstantially reducing the ability of the road spray to elevate from aroad surface.

In a further configuration, the diffuser 300 can be a substantiallyplanar member extending along the longitudinal axis 16 from just aheadof the leading axle to just behind the trailing axle. This configurationaccommodates the construction of the tandem by the original equipmentmanufacturer and the occupation of the space above the leading axle andtrailing axle with cabling, hoses and struts. In those constructions ofthe tandem in which the space above the axles is clear, the diffuser 300can extend above and below the axles, thereby partially enclosing theaxles. In a further configuration, the diffuser 300 (either as singlemember or multiple component) extends across a majority of a widthbetween the wheels of the leading axle.

The diffuser 300 thus attaches between the axles of the axle assemblyand beneath the main frame to span the distance between the axlescreating an aerodynamic surface. This surface controls the air flowbeneath the semitrailer 12 eliminating the need for a lower door mountedpanel on the rear doors. The diffuser 300 also channels the air past alower bumper of the semitrailer 12 removing the air from the drag streamand also channels a portion of the controlled air to knock down roadmist during rain.

As shown in FIGS. 8 and 9, in those configurations of the semitrailerhaving a container with a rear end 40 of the container including a pairof openable doors 42 as known in the art, each door 42 can include avertical flap 400 hingedly connected to the door 42 along an outsideedge and a horizontal flap 402 hingedly connected along a top of thedoor 42. The vertical flap 400 is movable between an extended positionextending generally rearward from the rear end 40 of the container to aretracted position wherein the flap 400 is generally parallel to thedoor 42.

In one configuration, at least a bottom hinge 404 and a top hinge 406connect the vertical flap 400 to the door 42, wherein the hinges 404,406, are mechanically connected such that actuation of the bottom hinge404 will impart actuation of the top hinge 406. A rod or bar can form aninterconnect between the hinges 404, 406 for imparting common actuation.

In one configuration, the vertical flap 400 includes at least twoattachment points to the door of the container. Each attachment includesa leaf or plate 408 affixed to the flap 402, wherein each plate 408includes a barrel 410. The plate 408 can be any configuration asdictated by the selected material of the plate 408 and the flap 402. Inthis configuration, the plate 408 is attached to the door 42 to locatethe barrel 410 adjacent to an existing hinge connection between thecontainer door 42 and the container. To install the flap 402, a hingepin 412 is removed from the corresponding hinge 404 or 406 on the door42 and the barrel 410 of each of the plates 408 affixed to the flap 402is aligned with the barrel 420 of the existing hinge 404, 406. Anextended hinge pin 412 is then located in the existing hinge 404, 406and the barrel 410 of the affixed plate 408 of the flap 402. The flap402 is thus rotatably mounted to the container.

Referring to the drawings, a linkage 414 which is separate from thehinges 404, 406 links the flap 402 to the door 42. The linkage 414includes a generally U-shape base 416 having a closed end of the Urotatably connected to the door 42, such as by a coupler or channelbracket. Each leg of the U shape base 416 pivotally connects to an arm418 which in turn is pivotally connected to the door 42. The closed endof the U shape base 416 forms the rod or bar that interconnects thehinge 404, 406 (or linkages) for imparting common actuation.

With respect to the horizontal top flaps 402, these flaps 402 can behingedly connected to the container door by affixing a hinge plate 422to the flap 402 and to the door 42 and secured by a pin 421 so that theflap 402 is rotatable between a closed position generally parallel tothe door 42 and an open position extending away from the door 42. Whilethe top flaps 402 can be selectively rotated between the open and closedpositions by any of a number of mechanisms, a satisfactory mechanismincludes a first link 424 having a first end pivotally connected to thehorizontal flap 402 at a distance from the axis of rotation of thehorizontal flap 402. A second end of the first link 424 is pivotallyconnected to a slider 426, wherein the slider 426 is connected to thedoor 42 to vertically slide along a vertical direction. In oneconfiguration, the slider 426 can be pulled vertically downward with apivoting bar actuated by pushing, causing the horizontal flap 402 torotate downwards toward the container door 42. Conversely, to disposethe horizontal flap 402 in the open position, the slider 426 is urgedupward by pushing causing the flap 402 to rotate to the open position.

Thus, the system provides an aerodynamic system for the rear of thecontainer having four movable flaps—two vertical side flaps 400 and twohorizontal top flaps 402—and an axle diffuser 300, as set forth below.

Generally, the rear flaps 400, 402 attach to the top and side of therear end of the semitrailer, including a side flap 400 and top flap 402for each door 42. The side flaps 400 include an aerodynamic panel 430and a mounting that uses the door hinges for swing doors and the doorframe for roller doors. The aerodynamic panel material can be plastic,metal, or other semi-rigid to rigid material, including fabric in aframe. To mount the aerodynamic panels 430 to the door 42 and adeployment device, the respective flap 400, 402 is mounted to the truckby the above described method and is deployed by moving the panel 430into the open position through the use of a pivoting bar. The pivotingbar locks open and closed through the use of the above-described pinsystem.

In a further configuration, the present disclosure provides forstreamlining the semitrailer main frame 14. In this configuration, themain frame 14 includes two and sometimes three (or more) elongate beamsextending along the longitudinal axis 16, wherein a multitude of crossbeams extending transverse to the elongate beans to provide a rigidframe upon which decking is attached to form the floor or deck of thesemitrailer.

In this configuration, a covering 502 is affixed across the bottom (orexposed edge) of the crossbeams to form a substantially continuousundersurface of the semitrailer as shown in FIG. 5. It is contemplatedthe covering 502 extends over substantially the entire area of theunderside of the semitrailer—even between the wheels and the bottom ofthe main frame. The covering 502 can be any of a variety of materialssuch as sheet metal, composites, plastics such as polycarbonate, or eventightly drawn fabrics.

The semitrailer includes a covering 502 that runs either longitudinallyor horizontally along the bottom of the main frame covering thesupporting I-Beams (transverse beams), thereby shielding the beams fromthe passing air flow. The covering 502 can be any material that islightweight, durable, weather resistant, road debris resistant. (oil,diesel, gas, tar, mud etc.)

The covering 502 can be attached by any of several methods includingtracks, clips, screws, bolts, flashings etc. It is contemplated theI-beam cover can extend all or a portion of the semitrailer bottom—frontto back and side to side.

Referring to FIGS. 10, 11, and 17, in another configuration, a fairing101 includes a pair of opposing lateral surfaces 109 and a leadingsurface 111. The pair of opposing lateral surfaces 109 are separated bya distance that is substantially equal to the width of the semitrailer.The distance can vary in width depending on the semitrailer size,design, and to maximize the aerodynamic advantage of the system. By“substantially equal to the width of the semitrailer,” it is meant thatthe opposing lateral surfaces 109 are spaced inwardly from the perimeterside edge of the semitrailer 10 by approximately zero to twenty-four(24) inches and more preferably between zero and eight (8) inches.Alternatively, all or a portion of the lateral surfaces 109 can protrudeapproximately zero to four (4) inches from the outer perimeter side edgeof the semitrailer. The leading surface 111 substantially spans thedistance between the opposing lateral surfaces 109 and defines a bow 113to reduce a drag coefficient of the fairing 101. As shown in FIG. 15 anddescribed below, in one configuration, the bow 113 is formed of twointegrally connected panels 103, 105. The panels 103, 105 can eachinclude an upper lip 187 extending forward from the bow 113 and asidewall 189 integrally connected to a corresponding edge of the lateralsurface 109.

The bow 113 can be flat, curved, bulbous, arched, or angled, have a highor low chin, and can have any of the following shapes: tumblehome,plumb, raked, spoon, etc. Further, the bow 113 can be curved or bulbousin the center and substantially flat along the remaining surface. Theposition of the bow 113 on the undercarriage 12 of a semitrailer 10 canbe adjusted according to the vehicle or truck type and the load type.The lateral surfaces 109 can be planar or can have at least one of aconvex and concave portion. As shown in FIGS. 14, 15 and 16, in oneconfiguration, the leading surface 111 is formed of two flat,half-bulbous, or slightly-curved panels 103, 105. The leading surface111 can include at least one intake opening 149 having a diameter rangeof approximately six inches to approximately four feet. In oneconfiguration, as shown in, for example, FIG. 15, the leading surface111 includes two intake openings 149 spaced approximately at least onefoot apart from each other for a 45-53 foot semitrailer. The openings149 can include a venting duct 151 fluidly coupling each intake opening149 to either an exit-opening 155 in the bottom surface 115 as shown inFIG. 15, or an exit-opening in each of the lateral surfaces 109 as shownin FIG. 16. In one configuration, the exit-openings, for exampleexit-opening 155, have a cross-sectional area that is less than across-sectional area of the intake opening, for example, intake opening149. In another configuration, the exit-openings have a cross-sectionalarea that is equal to a cross-sectional area of the intake openings.When a tractor-trailer is traveling, the air follows a flow path throughintake opening(s) 149 in the leading surface 111, through the ventingduct(s) 151 and either out the exit-opening(s) 155 in the bottom surface115 as shown in FIG. 15 reducing pressure and drag from the bottomsurface 115 and along the lateral surfaces 109, or, out theexit-openings 155 in each of the lateral surfaces 109, as shown in FIG.16, reducing pressure and drag on the lateral surfaces 109.

In one configuration, the bottom surface 115 of the fairing 101 isspaced from the undercarriage 12 of the semitrailer 10 and spans an areabounded by the lateral surfaces 109 and the leading surface 111.

In another configuration, the fairing 101 includes a trailing surface117 spaced from the undercarriage 12 of the semitrailer 10, the trailingsurface 117 substantially spanning the distance between the opposinglateral surfaces 109. Back panel 191 is shown in phantom so thattrailing surface 117 can be seen. The trailing surface 117 is spacedfrom the wheel set and lowers the drag coefficient of the fairingassembly 101. The trailing surface 117 extends from a spaced positionfrom the underside of the semitrailer 10 to a position adjacent theunderside of the semitrailer 10, and intermediate the wheel set and thefirst position 119 such that the trailing surface 117 is angled. Thesecond position 121 of the trailing surface 117 can be between one (1)inch and eighteen (18) inches from the underside of the semitrailer 10and more preferably between two (2) and nine (9) inches. The bottomsurface 115 and the trailing surface 117 substantially enclose a volumebeneath the semitrailer 10. By “substantially encloses” it is meant thatat least seventy percent (70%) of the undercarriage between the hitchand wheel set is enclosed by the fairing assembly 101.

In another configuration, as shown in FIG. 11, the drag force reductionsystem 197 includes a frame 211 connected to the undercarriage 12 of asemitrailer 10 and a skin 201 enclosing at least one portion of theframe 211. The frame 211 is sized to be intermediate the hitch and wheelset of a semitrailer 10. The position of the frame 211 on the undersideof the semitrailer 10 can be adjusted according to the vehicle or trucktype and the load type.

The frame 211 includes a front portion 203, a back portion 205, a bottomportion 207 and two opposing side portions 209 formed by sets of struts.In one embodiment, the struts are metal, plastic or PVC. The sideportions 209 are spaced at a distance that is substantially equal to thewidth of the semitrailer. The back portion 205 is spaced from the wheelset of the semitrailer 10 and includes a top edge 213. In oneconfiguration, the top edge 213 is spaced from the undercarriage of thesemitrailer 10. For example, the back portion 205 can be spaced betweentwo and nine inches from the undercarriage 12 of the semitrailer 10.Preferably, the space is approximately six inches. The back portion 205of the frame 211 extends at an obtuse angle relative to the bottomportion 207.

The frame 211 can have interconnecting modular sections. Preferably, themodular sections are approximately 1 foot to 20 feet wide. Morepreferably, the modular portions are approximately 2 feet to 10 feetwide. The side portions 209 can be planar or can have at least one of aconvex and concave portion. The frame 211 can further compriseaerodynamic fin portions 215 extending from the side portions 209 of theframe 211.

The skin 201 encloses at least one portion of the frame 211 reducing adrag coefficient of the system. In one configuration, the skin 201substantially encloses the front portion 203, the side portions 209 andthe bottom portion 207 of the frame 211. In another configuration, theskin 201 substantially encloses the back portion 205 of the frame 211.The skin 201 can be made from one or more than one of the following:polycarbonate, ABS plastic, metal, rubber, fabric and polyurethane.

In a configuration of the invention, the frame 211 is modular and can beused as a storage system, wherein any singular modular portion 201 isenclosed and includes a resealable access port (not shown) or whereinmultiple modular portions are enclosed to form one storage area whichincludes a resealable access port (not shown).

The front portion 203 may include at least one intake opening 249. Inone configuration, the front portion 203 includes two intake openings249 spaced at least approximately 1 foot apart from each other on a45-53 foot semitrailer. The openings 249 may include a venting duct 251fluidly coupling each intake opening 249 to either an exit-opening inthe bottom portion 207 or an exit-opening 255 in each of the opposingside portions 209. When a tractor-trailer is traveling, the air followsa flow path through intake opening(s) 249 in the front portion 203,through the venting duct(s) 251 and either out the exit-opening(s) 255in the bottom portion 207 reducing pressure and drag from the bottomportion 207 and along the side portions 209 or out the exit-openings 255in each of the side portions 209 reducing pressure and drag on the sideportions 209.

As shown in FIGS. 10, 12, and 13, the drag reduction system may includea back unit 301 for mounting to a back planar surface of the semitrailer10. The back unit 301 includes either one frame 301 or two half-frames(also referred to herein as first and second frames) 303 that togethercircumscribe a back planar surface of the semitrailer 10. The frame 301or half-frames 303 are formed of a plurality of struts 305 and include abase portion 307. In the one frame configuration, the frame 301 isapproximately pyramidal. In the one frame 301 configuration, the frame301 includes a base portion 307 arranged proximate the back planarsurface of the semitrailer 10 and a protruding portion 309 arrangeddistal to the back planar surface of the semitrailer 10. The first andsecond frames 303 can each form approximately ½ of a pyramid. The baseportion 307 of the one of the half-frames 301 circumscribesapproximately half of the back planar surface of the semitrailer and thebase portion of the second frame circumscribes approximately the otherhalf of the back planar surface of the semitrailer 10. In thisconfiguration, each half-frame 303 includes a center post 319 and guidelock for locking the half-frame 303 on to the rear-end of thesemitrailer 10 during installation and for releasing the guide lock uponremoval of each half-frame 303.

A material 311 substantially encloses the back unit frames 301 or 303.To secure the back unit to the semitrailer 10, hinges 313 are fixed tothe back planar surface of the semitrailer 10 as well as hinge bolts forreceiving a first terminal end 317 of each strut 305. One end of eachstrut 305 includes a pivoting connector arranged to engage one of thehinge bolts. It should be appreciated by those having ordinary skill inthe art that other connectors and anchors can be used to secure the backunit to the semitrailer, including but not limited to anchors, swiveljoints, connectors, and vertical anchors.

Preferably, the material 311 is flexible and pulled taut around theframe 301. Although the material 311 is set forth as enclosing the frame301, it is understood the material 311 can be connected to the frame 301to be within the volume defined by the frame 301. However, suchconstruction requires more fasteners connecting the material 311 to theframe 301.

This invention being thus described, it will be obvious that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention and all suchmodifications are intended to be included within the scope of thefollowing claims.

1. A drag force reduction system comprising: (a) a semitrailer having amain frame extending along a longitudinal axis and a subframe movablyconnected to the main frame between a first position along thelongitudinal axis and a second position along the longitudinal axis; (b)an axle assembly attached to the subframe, the axle assembly includingan axle, a plurality of wheels and a suspension; and (c) a fairinglocated under the main frame and separated from the axle assembly alongthe longitudinal axis by a given spacing, the fairing movable relativeto the main frame to maintain the given spacing between the axleassembly and the fairing independent of the subframe being in the firstposition or the second position.
 2. The drag force reduction system ofclaim 1, wherein the fairing is slidably connected to the main frame. 3.The drag force reduction system of claim 1, wherein the fairing isslidably connected to the axle assembly.
 4. The drag force reductionsystem of claim 1, wherein the fairing includes a fairing frame having amounting portion and a frame retaining portion, wherein the mountingportion is movable relative to the retaining portion along thelongitudinal axis.
 5. The drag force reduction system of claim 1,wherein the fairing is connected to the subframe at the given spacing.6. The drag force reduction system of claim 1, wherein the fairing isaffixed to one of the axle assembly and the subframe.
 7. The drag forcereduction system of claim 1, wherein the fairing is connected to thesubframe and translatable relative to the subframe.
 8. The drag forcereduction system of claim 1, wherein the subframe can be located at anyof a multitude of positions.
 9. The drag force reduction system of claim1, wherein the given spacing is adjustable within a predeterminedfairing range of motion.
 10. The drag force reduction system of claim 1,wherein the fairing includes a bottom and a leading apex formed of aplurality of converging planar regions.
 11. The drag force reductionsystem of claim 1, wherein the fairing includes a bottom surface and atrailing surface, a leading surface and lateral surfaces, the bottomsurface and the trailing surface substantially enclosing a volumebeneath the semitrailer.
 12. The drag force reduction system of claim 1,wherein the axle assembly includes a leading axle and a trailing axle,each of the leading axle and the trailing axle having at least twowheels for rotation relative to the main frame; and a diffuser extendingabout a portion of the leading axle, the diffuser extending along amajority of the distance between the wheels of leading axle, wherein thediffuser directs a passing air flow toward the ground.
 13. The dragforce reduction system of claim 1, the fairing includes an intakeopening and at least one flow path fluidly connecting the intake openingand an exit-opening formed in the fairing.
 14. The drag force reductionsystem of claim 13, wherein the at least one flow path includes at leastone venting duct extending from the intake opening to the at least oneexit-opening.
 15. The drag force reduction system of claim 1, whereinthe main frame further includes a plurality of elongate beams extendingalong a longitudinal axis and a plurality of cross beams connected tothe elongate beams and extending transverse to the longitudinal axis, anupper surface of the cross beams and the elongate beams supporting adecking and the decking, the elongate beams and the cross beams defininga plurality of cavities opening to an underside of the semitrailer;wherein a covering on an underside of the semitrailer substantiallyoccludes the plurality of cavities.
 16. The semitrailer of claim 15,wherein the covering is connected to the elongate beams and the crossbeams.
 17. The semitrailer of claim 15, wherein a portion of thecovering is disposed between the wheels and one of the elongate beamsand the cross beams, and wherein the covering comprises a materialselected from the group consisting of a polymer, composite, laminate,metal, and plastic.
 18. The drag force reduction system of claim 1,further comprising a closable container on the main frame, the containerhaving a rear end and a pair of doors movable between a closed positionand an open position, each door hingedly connected to the container topivot about a vertical axis; a vertical flap; at least an upper hingeand a lower hinge hingedly connected to one of the doors and thevertical flap to pivot the vertical flap about a vertical axis; and aninterconnector extending between the upper hinge and the lower hinge,such that upon movement of the lower hinge from an open configuration toa closed configuration, the upper hinge moves from an open configurationto a closed configuration.
 19. A method comprising: (a) providing asemitrailer having a main frame extending along a longitudinal axis anda subframe movably connected to the main frame between a first positionalong the longitudinal axis and a second position along the longitudinalaxis; (b) providing an axle assembly attached to the subframe, the axleassembly including an axle, a plurality of wheels and a suspension; (c)providing a fairing located under the main frame and separated from theaxle assembly along the longitudinal axis by a given spacing; and (d)moving the fairing relative to the main frame to maintain the givenspacing between the axle assembly and the fairing independent of thesubframe being in the first position or the second position.
 20. Themethod of claim 19, wherein the fairing is slideably connected to one ofthe main frame, the subframe and the axle assembly.